Saw-blade



n. w. PITTMAN.

SAW BLADE.

APPLICATION HLED- MAN. I2. 1.918.

Patented Nov. 11, 1919.

3 vwewtoz UNITED STATES PATENT OFFICE.

REINHART W.PITTMAN, OF NEW YORK, N. Y. ASSIGNOR, BY MESNE'ASSIGISTMENTS, T0 HENBYC. IPIT'I1VIAN, OF HACKEN SACK NEWJERSEY.

SAW-IBLAIDE.

Specification 0f Letters Patent.

Original applicatiqn filgd November 30, 1917, Seria11l'o. 204,482. Divided and this application fi1ed March 12, 1918. Sgrial N0. 221,902.

T0 all whom z't may concern:

Be it known that I, REINHART W. PI'IT- MAN, a citizen of the Unitecl Stabes, and a resident of the borough of Manhattan, in the oity, county, ancl State 0f New York, have invented certain new and useful Saw- Blaclesof wl1ich the following is Ja speoificatlon.

This invention.relates 130 saWbl2ucles, par;

ticularly back -saw blades, and it is tl1e ob ject of the invention t0 provide an i1nprov ecl' saw blacle whereby t0 facilitate the as sembling of the blades in piles withthe toothed. eclge 0f a blacle alternating withthe back edge of acljacent blades 'and to project the toothecl edge of the blacles a predetermined distance beyond the back edge of alternating blacles whereby to facilitate he harclening o1 tempering of the toothecl Zone only of a plurality of blacles simultaneously.

In the orclinary method 0f hiurdening saw blades a plurality of saw blacles ar6 sirnultaneously treated in a loose and separater]. conclition o1 state with zthe result that-all parts 0f the bladaor bl2'xdes are tempered or hardened thereby ni1aking the blade rigid ancl inflexible ancl should the blacle be bent or buCklecl cluringthe' cutting 01 sawing of a piece of stock the saw Will break. T0 ov'ercome this disaclvantz'mge the toothed Zone and the eclge portion of a blacle only is hardned 01 tempered and. the body ortion 'of the blacle left substzintially in its normal flexible conclition 01 pliable state. The known methods of only tempering ohe toothed zone of saw blacles are uncertain -and'-unreliable in that, especially in the tempering of saw blacles the teeth ofwhich a1e of ve'ry fine pitch, invariably only the face and immecliate acljacent portions of the teeth areprovidecl With a face tem]pering 01 hardenin'g with the result that-when the saw is usecl this surface tempering chips or quickly wears olf and the utility 0:E the Same is problematical.

It 'is' the principal objeot of the inventmn toovercome the above disaclvantages by provicling an improvecl form of 'blade to permit of theassembling ancl supporting 013 a plurality 0f blacles, whereby the surface of the toothecl z011e o f the blacles on1y is -eXj- E0secl and. adapt'g'd to be subjected to the ardening eperatwn, a;nd thelmrdenmgoi the entire toothecl Zone 0f the respective blades assured. V

-The presbnt application is a division of my copencling' application filecl November 30 1917, Serial N0. 204,482, and in connection with this applicacion I have shown a 1'noclified methocl and means of assembling and supporting a plurality 0f blacles.

In the clrawing accompanying and fofming a part of this specification, Fig11re l is a 'perspective view of n1y improved saw member '01 bar 130 retain a pile of blades in assexhbled position While clampingthem in the' 'supporting 1ne1nbers showh,in Figs. 3 and 4; and Y Fig. 6 is a perspec'ive view of the encl portion 0f a clamping bar t0 engage the encl blades o'fthe pile.

Similar characters 0f reference designate lik partsthroughout the difierent views 0f the clrawing 1 In carr'yinp out the invention the saw blade blank r i s shearecl fro1n a sheet of 1netal to' the desirecl Wiclth ancl length after which portions of Opposite ends of the blank are stamped ther'efrorn to rouncl th'e ends,

as shown at 8,-ancl pro'viclecl with the usual perforations 9 for the engagementof means t0 secure the blacle in a saw carrying frame. Simultane'zously with the rouncling of the ends of he blank the blank is provicled with gage port'ions, in the for1n of recesses 10 stam'pecl froni portions of the blank adjacent opposite ends ancl preferably within theperforatecl portion 0f the blank It Will be obvious that these gage portions may be stampecl from the blank eitherpreviously 01' subsequent to the rouncling of the encls and the 'perforatingof the blanks. The teeth 11 of the blacle are formed in a suitable mann er ancl Preferably' in tl1ek edge 0f locatecl und extencl between saicl gage portions, with the lutter substantiully 0'f a clepth equivulent t0 the depthof tl1e t0oth zone 01 bel0w tl1e bnse of die teetl1, so that the teeth 0f tl1e blacle extencl beyoncl tl1e bottom 0f ehe recesses.

mit; 0f the asse1nbling 0f a, pile 01: bladee t0 simultaneously lmrden 01 te1nper the toothecl zone 0f a plurality 0f blacles. V1tll a blacle as fonned with the gage portionsus above set f0rtl1 the blacles are asse1nblecl Sicle by sicle witl1 t-l1e toothecl eclge of blades alternating with the back eclge 0f successive 01 adj acent blacles. After tl1e clesirecl nu1nber 01 blades have been assemblecl in tl1is relation a block 01 bar 12 0]": a width substzintially equal to the clistance between tl1e back edge und t0othecl zone 01 bott0m 0f the teet-h 0f the blacles, und 0]f a, length substantiully the szune us the length of the blades, und having opposite recess portions 13 adjacent opposite encls 01 a f011n substantiully the szune as the gage port-i0ns 10 in the blades, (Fig. G) is plncecl contiguous t0 the blade at oppo'site encls 01 the assembled 01 pile 0f blacles. The blacles a1e retainecl in tl1is ussemblecl position Willi a ba112 ab opposite encls by a clamping1nexnber 14 us sh0wnin Fig. 5 embracing tl1e assemblecl bladeg at the guge portions. Tl1e clamping n1e1nber 14 comprises a pieee 01 resilient metal, such es wire, bent upon itself with 0ne portion 15 eurvecl as shown t0 inorease tl1e inherent springiness ortension thereof und fonnecl with a hook 01 100p 16 f0r engagement 015 tl1e free encl 0f ehe portion 01" the 1nember opposite the portion 15 und Whi0h operates 130 clmW tl1e elmnping n1e1nber firmly aguinst the gage portions 0f tl1e blacles und pr0ject tl1e toothecl eclge beyond the back eclge 0f alternate blacles t0 the positi0n substantiully z1s sh0wn in Fig. 2. The pile 0f blacles retuineclin ussemblecl position by tl1e members 14 is then placecl in a elmnping appuratus comprising a pair 0f clamping members t0 support tl1e pile 0f bludeg udjucent opposite ende und is shown armngecl tocurry tw0 piles 0f blades 01' asse1nblecl suw blades. The cla1nping members eonsist 0f a pair 0f juws 18 hzwing recesses 19 therein f0r ehe engage1nent 0f the bare 12 2113 opposite sicles 0f tl1e assen1blecl blacles t0 prevent lateral clisplacement 0f the assem bled blacles, und tl1e jaws zue clmwn 01 lockecl together by b0lts 01 tie rocls 20 passing tl1rough openings centrally 0f the aws. sVhen the asse1nblecl blacles 2ue securecl be tween the clzunping aws 18 tl1e clznnping 1ne1nbe1s 14 a1e removecl when the asse1nblecl blarles are in condition t0 be subjectecl t0 the haudening 0r te1npering operation.

The blacles when assemblecl und clflmpecl between the cla1nping jmvs 18 as shown in Figs. 3 anal 4 ure in conclitionto be subjecl3ecl 120 the harclenihg treatment, ancl in this' Q0n.

cliti0n a1e pluced in u heating furnac'e t0 be heatecl t0 the clesirecl degree. After the ussemblecl blacles hzwe been heatecl t0 tl1e neoessary clegree the carrier Witli tl1e bla'cles is removecl fron1 the furnace und the blucles suclclenly chillecl by plunging in a cooling 113 is the 0bject 0f the gage portions t0 per balzh. lt Will be noted that tl1e entire toot-l1ecl zone ancl the back eclge of ehe blades are tl1e onlj portions 0f tl1e blacles whicl1 are subjectecl t-0 contaet with tl1e cooling liquid by supporting ehe blacles in tl1e manner above set f0rth with the 1esult ahnt the tooth0cl zone 0f tl1e blacles only will be te1nperecl Witl1 a scale harclening 011 the back eflge 0f the blades, und filmt the bocly portion 0f the blacles not being exposecl Will not be silbjeetecl t0 contact with the cooling liquid und Will therefore re1nain substantially in their original flexible conclition, und may be flexecl after ehe harclening 0f the toothecl zone without liability of bi*eakage 0f the bla des. Furthennore, by the harclening 0'f the eclge portionof the blacles es well es the toothed Zone the clisisorting und warping 01: l1e blacle clue t0' changes in the 1nolecular structure 0f tl1e 1netal as the blende is subjected t0 the harclening process is 0bviated. y V

As is Well known in tl1e harclening 0f 1netal the suclclen cooling 0f the l1eatecl metal tends 130 harclen the 1netal t0 an excessive clegree, und by assembling tl1e blacles in the 1nanner as above set forth und subjecting the blades in such asse1nblecl conclition so a te1npering bath the te1nper 0f the harclenecl toothed zone und tl 1e edge ortion 0f the blades only may be dmwn t0 tl1e clesirecl teinperwithout afleeting any otl1er portion 0f the blade.

Having thus clescribecl my invention, I elain1:

1. As u new urticle of nmnufacture u suw blucle c01nprising a blank l1zwing teetl1 formecl along the edge, und guge portions in the eclge 0f' the blank acljucent opposite encls f01 the purpose' speeified.

2. As a new article of nmnufacturea suw blacle comprising a blank hzwing teeth fonnecl along the eclge ofthe blank with a recess in the eclge 01: the blank acljacent 013- posite ende 0f a, clepth equivalent t0 tl1e clepth o1 the toothecl zone of tl1e blacle for the purpose specifiecl.

3. As u new article 0f manufucture usuw blade comprising u blank having teeth formecl along one eclge 0f the blacle with u reeess in the eclge of the blacle with the teeth aclj acent opposite encls of tl1e blacle with the teeth extencling beyoncl the bottom of the recesses f01 the purpose specifiecl.

4. As a new article 0f manufacture a saw blade comprising u blank h2iving teetl1 foiinecl along 0ne eclge, und gage portions at opposite encls 0f l;he tootl1ecl po1tion with the t00thed' zone 015 the blade e2@tending loe the base 0f the teeth and with the toothed zone and edge 0n1y of the bladehardened.

7. As a 110W article of manufacture 2tsaw blade having teeth formed along the edge and the toothed z0ne and edge of the b1ade hardened und the body ortion of the blade maintained in an unhardened state, and said b1ade having gage portions at opposite ends ior the purpose specified.

Signed a1; New York city, in the county of New York, and State of New York this 8th day of' March, 1918.

REINHART W. PITTMAN.

Gopiu o! th1s patent may be obtained tor five cents each, by addressing the Gommissioner of Patents, Washington, D. G. 

